Orbital aperture morphometry in Brazilian population by postero-anterior Caldwell radiographs

Morphometric analysis of the supraorbital region for sexual dimorphism: A study on Brazilian adult dry skulls

Introduction

Pelvis, long bones, and skull are good indicators of sexual dimorphism. In the skull, the supraorbital region is considered a highly sexually dimorphic part. Thus, the present study aimed to analyze the sexual dimorphism of Brazilian adult dry skulls using conventional and geometric morphometry.

Materials and Methods

Conventional morphometry was performed on 179 skulls, through the analysis of six linear measurements. For geometric morphometry, 89 skulls (right side) were selected and seven landmarks were considered. Generalized procrustes analysis, principal component analysis, and linear discriminant analysis were then carried out.

Results

All linear measurements presented differences between both sexes. Geometric morphometry showed that 77.05% of the sample variation could be explained by the first three principal components. Moreover, considering the centroid size, there was a difference in shape between the sexes. Geometric morphometry classified sex correctly in 77.32% of the skulls and conventional morphometry from 60.89% to 73.74%.

Conclusions

According to the analyses, the supraorbital region presents significant sexual dimorphism in Brazilian adult dry skulls. Moreover, it can be analyzed efficiently by both conventional and geometric morphometry, although the latter seems to be slightly more accurate.

Morphometric evaluation of the orbital region for sex determination in a Saudi Arabian population using 3DCT images

In forensic anthropology, the analysis of variations in the orbitometric features plays a crucial role in identifying the sex of a skull detached from its skeleton. Therefore, it is essential to create population-specific values to maximize the accuracy rate of sex estimation. The objective of this study was to evaluate the orbital region morphometrically for sex determination in a Saudi Arabian population using CT scan images. This study included 456 CT images (228 males and 228 females; age range, 18-58 years). Six orbital measurements and the orbital index of both sides were evaluated to determine sexual dimorphism and laterality using an independent t-test. Sex was estimated using discriminant function analysis. Based on the orbital index, the orbit was classified into megasemes, mesosemes, and microsemes. All the measurements were significantly greater in males than females, but the orbital index showed no significant sexual dimorphism. No significant asymmetry was found in all orbital dimensions. The univariate discriminant function of the orbital measurements showed an accuracy rate between 83.8 and 70%. The multivariate analysis classified the orbital dimensions into male (93%) and female (92.1%) to the highest level of accuracy. In Saudis, the megaseme category was the most prevalent form of orbit. The right orbit height (83.8%), left orbit height (80.7%), right orbit width (79.4%), and left orbit height (79.4%) were the most reliable variables that could be used in sex determination. According to multivariate analysis, the overall accuracy rate for determining sex was 92.1%. While the present study data may not be used alone for sexing a complete skull, there must be various occasions in which this new standard will contribute to determining sex in forensic contexts.

Use of Width Measurements Taken from the Upper Face Region in Sex Determination

Objective: In today’s world, experts are increasingly making identification and sex determination from skeletonized and dismembered corpses. For this reason, the question of which anatomical regions and bones will be used for sex determination is becoming increasingly important issue. One of the anatomical regions that stand out in terms of sexual dimorphism is the facial region and the elements that make up this region. Although studies have revealed that the width measurements in the face region, especially the bizygomatic width, are an important sex-discriminating variable, the other elements that make up the upper face region have not been adequately examined. The aim of this study is to look for an answer to the question of whether width measurements can be used in sex determination by focusing on the upper face region (especially the orbital aperture and its surroundings). Methods: In this framework, 5 width measurements were taken on CT (computerized tomography) images of 200 adult individuals (100 women, 100 men) aged between 18 and 75 years. These measures are: (1) interzygomatic width, (2) bimalar width, (3) orbital width, (4) biorbital width, and (5) interorbital width. The degrees of sexual dimorphism of the measures were analyzed by constructing univariate and multivariate discriminant functions. Results: The results of the analysis revealed that the ratio of correct allocation of sex by univariate functions ranged from 63.5% to 76.5%. It was determined that the variables that best the discriminator of sex were bizygomatic width (76.5%) and biorbital width (73%), respectively. Two variables were included in the most successful multivariate function that correctly separated the sex groups. These are bizygomatic width and orbital width measurements, and the correct sex determination rate of this equation was determined as 77%. Conclusion: Our findings reveal that the success of the width measurements in the upper face and orbital region is at a moderate level, therefore, in the medico-legal examinations the width measurements of the upper face region can be applied in cases where the bone elements forming the pelvis are not found.

Developmental changes of the facial skeleton from birth to 18 years within a South African cohort (A computed tomography study)

Skeletal remains are often found on a crime scene in which a forensic anthropologist is then consulted to create a biological profile, which includes the estimation of age, sex, ancestry and stature. The viscerocranium plays an important role in the formation of a biological profile. However, to utilise the viscerocranium for age estimation, population specific normative data and knowledge of the development of the viscerocranium is required. Therefore, this study aimed to investigate the developmental changes from birth to 18 years of age of the facial skeleton of individuals from a South African cohort. This study comprised of 239 computed tomography (CT) scans (128 males; 111 females). The viscerocranium was subdivided into five regions viz.: orbital, nasal, midfacial, maxillary and mandibular. The linear parameters in each region were correlated to age to identify the developmental growth patterns of the viscerocranial regions according to male and female. The measurements which displayed the highest correlations with age were used to develop formulas which could be used for age estimation. The results of this study showed that the measurements in the orbital, midfacial, maxillary and mandibular regions experienced rapid growth between 0 and 5 years of age, with the nasal region increasing steadily over time. It was noted that males displayed overall larger measurements than females except for the anterior interorbital distance and both right and left zygomatic arch lengths (ZAL). Although only the left orbital height, nasal aperture height and mandible width displayed statistically significant size differences according to sex (p ≤ 0.05). The measurements which showed the highest correlations to age were the zygomatic arch distance (r = 0.8842, p < 0.001), ZAL (right: r = 0.8929, p < 0.001; left: r = 0.8656, p < 0.001) and the mandible width (r = 0.8444, p < 0.001). Formulas were derived for the measurements that could be used to forensically estimate age within a subadult cohort.

Morphometric Analysis of the Orbital Aperture in North Indian Population: A Retrospective Digital Forensic Study

Introduction:

The morphometric variations seen in the orbital aperture play a significant role in forensic anthropology, for determining the personal and gender identification, especially in case of mass disasters.

Aim:

The aim of the present study was to evaluate the orbital aperture dimensions along with interorbital distance as observed on posteroanterior (PA) cephalograms for personal and gender identification.

Materials and Methods:

The present retrospective study was conducted to evaluate the morphometric dimensions of orbital aperture seen on PA cephalogram taken using PLANMECA digital machine and ROMEXIS software. The height and width of the orbits along with the interorbital distance were measured using measuring tools in the accompanying software. Data were analyzed using SPSS software version 21.0.

Results:

All the linear measurements such as orbital height, orbital width, and interorbital distance were significantly greater in males than females in the North Indian population with P = 0.001. The present study found 84.8% accuracy after subjecting the obtained value to discriminant function analysis.

Conclusion:

The morphometric analysis of the orbital aperture using postero-anterior cephalogram can be used as an adjuvant for personal and gender identification in forensic anthropology.

Orbital aperture morphometry in Indian population: A digital radiographic study

Background:

Morphological variations of the orbital aperture measurements may be used in forensic medicine as a parameter for determining sexual and ethnic identity of an individual.

Aim and Objective:

The aim and objective of this study was to evaluate the orbital aperture dimensions in Indian individuals and verify their relationship with gender.

Materials and Methods:

A retrospective study was conducted using digital posteroanterior view radiographs of 50 males and 51 females, which were taken using NEWTOM GIANO-CEFLA SC machine (81 kVp, 10 mA, and 6.6 s). The orbital aperture measurements were carried out using NEWTOM software NNT version 5.5. The maximum width and height of the orbits and the inter-orbital distance were measured. The obtained data were subjected to t-test and discriminant function analysis.

Results:

In the t-test, significant differences in orbital width and inter-orbital distance were obtained between the genders. On subjecting the data to discriminant function analysis, result was obtained with 86.1% accuracy rate in gender determination.

Conclusion:

If the discriminant score is >1.0365, the skull is likely to be of a male, and if it is <1.0365, it is likely to be of a female. Therefore, orbital aperture measurements can be used for gender determination in human identification.